Hemostasis valve, system and assembly

ABSTRACT

A hemostasis valve including a collapsible membrane in a portion of a through-lumen. Fluid pressure in a chamber surrounding the collapsible membrane assists in sealing the collapsible membrane around an operating device inserted through the hemostasis valve. Different mechanisms for mechanically deforming the collapsible membrane to assist in sealing are disclosed. Also, a system for continuously flushing a vascular catheter connected to a hemostasis valve at a rate of 0.10 to 10.0 cubic centimeters per minute, and a hemostasis valve assembly including an expandable reservoir which stores liquid volume under pressure.

This application is a Divisional of application Ser. No. 08/735,521,filed Oct. 23, 1996, which application is incorporated herein byreference, now U.S. Pat. No. 5,895,376.

FIELD OF THE INVENTION

This invention relates generally to hemostasis valves used indiagnostic, therapeutic and interventional vascular procedures, and moreparticularly to the sealing mechanisms in such devices and to relatedsystems, including those for flushing.

BACKGROUND OF THE INVENTION

Hemostasis valves (also sometimes referred to as “Y-connectors” and“Touhy-Borst valves”) are commonly used in certain medical procedures. Aguide catheter is connected to the distal end of the valve, and anoperating instrument, such as a guide wire or balloon catheter, isinserted into the proximal end and through the guide catheter to thedesired location in the patient. After the operating instrument is inplace, the valve is closed to keep blood from leaking out of the patient(“hemostasis”).

One of the problems with current hemostasis valves is that they arecumbersome to operate, taking a long time to open and close. Most employa Touhy-Borst sealing mechanism such as that described in U.S. Pat. No.4,886,507. A threaded cap deforms an O-ring into a tapered opening untilthe O-ring clamps down on the operating instrument. Each time theoperating instrument is adjusted, the cap must be unthreaded before andthen rethreaded after the manipulation. During the time that the valveis open, blood leaks from the patient and/or contrast media is lost.Inaccurate blood pressure readings also occur. There is also a risk ofair emboli when the valve is open, particularly when removing theoperating instrument.

Another problem with prior art hemostasis valves, such as Touhy-Borstvalves, is that significant mechanical force must be applied to theoperating instrument in order to maintain the seal. This is particularlya problem at higher system pressures, and when pressure spikes occur,such as when flushing the system with saline or introducing contrastmedia. The often delicate drive shaft of the operating instrument can becrushed by the force of the seal. The high force seal also preventsmoving the operating instrument while the valve is closed.

One attempt at addressing some of these problems is shown in the '507patent. In addition to a Touhy-Borst, this design includes a membranehaving a fixed circular opening for sealing shafts within a certaindiameter range. This sealing arrangement, however, still relies solelyon a mechanical sealing system which requires high shaft forces at highsystem pressures. It also incorporates the same threaded Touhy-Borstvalve, which requires the cap to be manually threaded in order to closethe valve. The fixed opening membrane would also be helpful only withoperating instruments in a particular diameter range.

Hemostasis systems typically have a perfusion port used to flush thesystem with saline in order to prevent blood clots from being formed.This is done by a technician periodically during the procedure, whichtakes time and may interrupt the procedure. The blood pressure readingsare also inaccurate during the flush.

What has been needed is a hemostasis valve which opens and closeseasier, maintains a seal at higher pressures without damaging theinstrument, and permits movement of the instrument while maintaining aseal. What has also been needed is a hemostasis system which reduces oreliminates the need for periodic flushing. What has also been needed isa hemostasis assembly which reduces blood loss and the risk of airemboli while the valve is open.

SUMMARY OF THE INVENTION

According to the present invention, a hemostasis valve, system andassembly are provided. The inventions can be used in a variety ofdiagnostic, therapeutic and interventional procedures, includingangiography, angioplasty, stent placement, drug infusion, intravascularultrasound, rotablation, and atherectomy.

In one aspect of the invention, a hemostasis valve comprises a valvebody having a proximal end for receiving an operating device, a distalend for connection to a guide catheter, and a through-lumen in the valvebody intermediate the proximal and distal ends. The operating device isinserted through the through-lumen and into the guide catheter. Achamber in the valve body surrounds the through-lumen and is filled withfluid under pressure. A collapsible membrane in a portion of thethrough-lumen is constructed and arranged such that the fluid pressurein the chamber assists in sealing the collapsible membrane around theoperating device.

In another aspect of the invention, a hemostasis valve comprises a valvebody having a proximal end for receiving an operating device, a distalend for connection to a guide catheter, and a through-lumen in the valvebody intermediate the proximal and distal ends. The operating device isinserted through the through-lumen and into the guide catheter. Thethrough-lumen comprises a proximal portion, a distal portion and anelastomeric sleeve therebetween. One of the proximal and distal portionsof the through-lumen is rotatable relative to the valve body between aclosed position wherein the elastomeric sleeve is twisted to seal aroundthe operating device and an open position wherein the elastomeric sleeveis sufficiently untwisted to unseal the elastomeric sleeve from theoperating device.

In another aspect of the invention, a system for flushing a vascularcatheter comprises a hemostasis valve and a vascular catheter forinsertion into a patient, sealingly connected to the hemostasis valve. Asource for providing flushing fluid under pressure is in fluidcommunication with the hemostasis valve. A mechanism controls the flowof said flushing fluid from the source to the hemostasis valve at a rateof about between 0.10 to 10.0 cubic centimeters per minute, therebycontinuously flushing the vascular catheter.

In another aspect of the invention, a hemostasis valve assemblycomprises a hemostasis valve which is moveable between a closed positionwherein liquid in fluid communication with a patient is sealed and anopen position. An expandable reservoir in fluid communication with theliquid in the hemostasis valve is moveable between expanded andretracted positions. The expandable reservoir is constructed andarranged such that, when the hemostasis valve is moved to the openposition, the expandable reservoir retracts toward the retractedposition so as to force liquid out of the open hemostasis valve.

These and other advantages and features of novelty which characterizethe invention are pointed out with particularity in the claims annexedhereto. However, for a better understanding of the invention and itsadvantages, reference should be made to the drawings which form afurther part hereof, and to the accompanying descriptive matter in whichthere is illustrated and described preferred embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross-sectional view of a first embodiment of ahemostasis valve according to the present invention, including a systemfor continuously flushing a vascular catheter and an expandablereservoir;

FIG. 2 is a cross-sectional view of a second embodiment of a hemostasisvalve according to the present invention; and

FIG. 3 is a perspective view of the clamp used in the hemostasis valveof FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, wherein like numerals designate likeparts, first and second hemostasis valve embodiments are shown in FIG. 1and FIGS. 2-3, respectively. The hemostasis valves of the presentinvention can be used with a variety of diagnostic, therapeutic, andinterventional operating devices as set forth above.

Referring to the first embodiment shown in FIG. 1, hemostasis valve 10comprises valve body 12 with proximal end 14 for receiving operatingdevice 19 and distal end 16 for connection to guide catheter 18. Astandard hose barb 15 is shown at proximal end 14 and a standard luerlock 17 is shown at distal end 16 for connection to guide catheter 18.

Valve body 12 includes through-lumen 20 through which operating device19 is received. In a portion of through-lumen 20 is a collapsiblemembrane 22 which seals around operating device 19. This sealing isassisted by fluid pressure from chamber 30 surrounding through-lumen 20.This pressure assist is advantageous in a number of ways. The lowerpressure differential between through-lumen 20 and chamber 30 makes iteasier to create a seal by mechanically deforming collapsible membrane22. Less mechanical force is consequently necessary for sealing, whichreduces the risk of damaging the drive shaft of the operating device andhelps permit manipulation of operating device 19, longitudinally andtorsionally, while maintaining a seal.

In the first embodiment of FIG. 1, chamber 30 is in fluid communicationwith through-lumen 20 through passage 32. Thus, for example saline orthe patient's blood can pass back and forth. This arrangement isparticularly helpful in dynamic high pressure situations because thehigh pressure tending to open the hemostasis valve is offset by the alsohigh pressure in chamber 30.

Collapsible membrane 22 is mechanically deformed in the first embodimentby turning adjustment knob 40 so as to twist elastomeric sleeve 44around operating device 19 to effect a seal. Adjustment knob 40 isbiased toward the closed position (shown) by coil spring 46 around valvebody 12 which is connected at its opposite end to stationary knob 42. Itwill be understood that a variety of other spring mechanisms could beemployed for this purpose. This arrangement permits better sensitivitywhen opening valve as well as automatic closure, which reduces the timethat the valve is open.

Elastomeric sleeve 44 is fixedly and sealingly disposed onto barbs 41,43 of adjustment and stationary knobs 40, 42. Sleeve 44 is preferablymade of a flexible biocompatible material such as silicone or latex. Thepreferred sleeve has a {fraction (3/16)} inch o.d., ⅛ inch i.d., and alength (measured between barbs 41,43) between 0.25 and 0.50 inches. Tohelp facilitate movement of operating device 19 while maintaining thevalve closed, it would be preferable to coat the inner side of sleeve 44with for example a hydrogel to provide a slicker surface.

Referring to FIGS. 2 and 3, a second preferred embodiment of ahemostasis valve is shown. In describing the second embodiment,attention will be focused to the relevant differences from the firstembodiment.

In the second embodiment, chamber 30 is not in fluid communication withthrough-lumen 20, but is instead isolated. Saline or other fluid isprovided to chamber 30 by high pressure fluid source 50 through port 51.Second port 52 is used to evacuate air or relieve pressure from chamber30 with valve 53. In this way, opening and closing of the hemostasisvalve can in fact be accomplished solely by selectively providingsufficient fluid pressure in chamber 30 to completely seal collapsiblemembrane 22 around operating device 19. A third port (not shown)communicating with through-lumen 20 could be used for pressuremonitoring, flushing, and/or injecting contrast media for example. Thefluid pressure in chamber 30 is preferably at least that inthrough-lumen 20. A more simple arrangement than the second preferredembodiment would eliminate both ports 51, 52 and have a constantpressure in chamber 30 sufficient to assist in sealing collapsiblemembrane 22 around operating device 19.

Collapsible membrane 22 is mechanically deformed by action of feet 61 ofclamp 60, best shown in FIG. 3. As with the first embodiment, a spring62 (here a compression spring) is used to bias the valve to a closedposition. Feet 61 extend into correspondingly shaped openings 57 inrigid outer wall 56 and deform outer elastomer tube 54 radially inward.This increases the fluid pressure in chamber 30 which in turn deformscollapsible membrane 22 to seal around operating device 19. Bothmembrane 22 and tube 54 are preferably made of latex. Membrane 22 has a{fraction (3/16)} inch i.d. and is 0.012 inches thick. Tube 54 has a ⅜inch i.d. and is 0.085 inches thick. They could also be made of siliconeor urethane, but a thinner wall for tube 54 would likely be required. Itwill be understood that a variety of other mechanisms could be used toradially direct pressure and that mechanical pressure could be applieddirectly to collapsible membrane 22 alone or in combination with fluidpressure to effect a seal.

Referring now to FIG. 1, system 70 provides a continuous flush of guidecatheter 18 and hemostasis valve 10. Saline is delivered to hemostasisvalve 10 through first port 75 at a rate of about 0.1 to 10.0 cubiccentimeters per minute, preferably about 1.0 cubic centimeters (1 ml.)per minute. High pressure saline is supplied by source 71, which ispreferably a saline bag at a pressure of about 300 millimeters ofmercury. The desired flow rate can be achieved by a variety of flowrestricting arrangements. The preferred arrangements are anappropriately sized orifice 72 and/or capillary tube 73. The preferredcapillary tube 73 is 30 gauge hypotube 0.6 inches long and having ani.d. of 0.006 inches. System 70 permits more continuous monitoring ofpressure with pressure monitor 92 by reducing or possibly eliminatingthe need for flushing with high pressure saline 90.

Referring again to FIG. 1, hemostasis valve assembly 80 includes bellows82 which acts as an expandable reservoir of liquid volume. Bellows 82 isconnected to hemostasis valve 10 by third port 81. It is preferably madeof an elastomeric material such as latex and should “saturate” (i.e., besubstantially expanded) at a mean pressure of about between 60 to 120millimeters of mercury, most preferably at a typical blood pressure ofabout 90 millimeters of mercury. It will be appreciated that a varietyof expandable reservoir arrangements other than a bellows could besuitable for this purpose, as for example one that relies on springs oranother mechanism instead of the inherent elasticity of the reservoir.

The liquid volume stored by expandable reservoir 82 under pressure has anumber of advantages. It reduces blood loss when hemostasis valve 10 isopened by replacing lost liquid with liquid from the retractingreservoir instead of blood from the patient. There is also a significantrisk of air emboli caused by the vacuum which is created when the distalend of operating device 19 is pulled out of proximal end 14 ofhemostasis valve 10. Expandable reservoir 82 helps force liquid out ofproximal end 14 of hemostasis valve 10 so as to prevent air fromentering. Expanding reservoir 82 is also helpful when hemostasis valve10 is closed. For example, it will tend to absorb pressure spikes, suchas those created by high pressure flushing 90 or injecting contrastmedia 94, by reservoir expanding instead of liquid leaking out ofhemostasis valve 10.

It should be understood that the present invention is not limited to thepreferred embodiments discussed above which are illustrative only.Changes may be made in detail, especially in matters of shape, size,arrangement of parts, or material of components within the principles ofthe invention to the full extent indicated by the broad general meaningsof the terms in which the appended claims are expressed.

We claim:
 1. A system for flushing a vascular catheter, comprising: (a)a hemostasis valve; (b) a vascular catheter for insertion into apatient, sealingly connected to said hemostasis valve; (c) a source forproviding flushing fluid under pressure, in fluid communication withsaid hemostasis valve; and (d) means for controlling the flow of saidflushing fluid from said source to said hemostasis valve at a rate ofabout between 0.10 to 10.0 cubic centimeters per minute, therebycontinuously flushing said vascular catheter.
 2. A system according toclaim 1, wherein said flow controlling means comprise a flow restrictingorifice.
 3. A system according to claim 1, wherein said flow controllingmeans comprise a narrow tube having a diameter and length appropriatefor achieving a predetermined flow rate.
 4. A system according to claim1, further comprising a pressure monitor.
 5. A system according to claim1, further comprising means for periodically flushing said vascularcatheter at a relatively high rate.
 6. A system for flushing a vascularcatheter, comprising: (a) hemostasis valve; (b) a vascular catheter forinsertion into a patient, sealingly connected to said hemostasis valve;(c) a source for providing flushing fluid under pressure, in fluidcommunication with said hemostasis valve; and (d) structure defining aflow restricting orifice that controls the flow of flushing fluid fromsaid source to said hemostasis valve at a rate of about between 0.10 to10.0 cubic centimeters per minute, thereby continuously flushing saidvascular catheter.
 7. A system according to claim 6, wherein saidstructure comprises a narrow tube having a diameter and lengthappropriate for achieving a predetermined flow rate.
 8. A systemaccording to claim 6, further comprising a pressure monitor.
 9. A systemaccording to claim 6, further comprising means for periodically flushingsaid vascular cather at a relatively high rate.
 10. A system forflushing a vascular cather, comprising: (a) a hemostasis valve; (b) avascular catheter for insertion into a patient, sealingly connected tosaid hemostasis valve; (c) a source for providing flushing fluid underpressure, in fluid communication with said hemostasis valve; (d) meansfor controlling the flow of said flushing fluid from said source to saidhemostasis valve at a rate of about between 0.10 to 10.0 cubiccentimeters per minute, thereby continuously flushing said vascularcatheter; and (e) means for periodically flushing said vascular catheterat a relatively high rate compared to said flow controlling means.
 11. Asystem according to claim 10, wherein said flow controlling meanscomprise a flow restricting orifice.
 12. A system according to claim 11,wherein said flow controlling means comprise a narrow tube having adiameter and length appropriate for achieving a predetermined flow rate.13. A system according to claim 10, further comprising a pressuremonitor.
 14. A system according to claim 10, wherein said periodicallyflushing means comprise a high pressure saline bag and a stopcock.